The adverb clause here is <span>"since the sun came out" - it gives some information about the timing of the event.
It modifies "feels" (actually I would say that it modifies the phase "feels warmer") - this "feeling" happens since the sun came out, that's when it started!</span>
I believe it is an active voice
I'm not using evidence from the book, but I can explain how the first person affects the story and reader. You can add the evidence when I give you the prompt answer. - First person point of view affects the story and reader because of the different it makes to the plot and whole setup of the story. First person changes the way the story is set up because it is one of the characters narrating the story. It affects the reader because when you are reading the book, you feel like you are the character in the story. It makes reading the story more enjoyable.
I would try to use attractive descriptive words, such as lush or shining, something to captivate their memory. If I had any good stories to tell about the place I would want to focus on those, since stories make them imagine themselves in that place and situation, possibly making them want to go. Finally, I’d show them any pictures that I took to really capitalize on the beauty or charm of the place I’m talking about.